/***************************************************************************

	Atari Tetris hardware

	driver by Zsolt Vasvari

	Games supported:
		* Tetris

	Known bugs:
		* none at this time

****************************************************************************

	Memory map

****************************************************************************

	========================================================================
	CPU #1
	========================================================================
	0000-0FFF   R/W   xxxxxxxx    Program RAM
	1000-1FFF   R/W   xxxxxxxx    Playfield RAM
	                  xxxxxxxx       (byte 0: LSB of character code)
	                  -----xxx       (byte 1: MSB of character code)
	                  xxxx----       (byte 1: palette index)
	2000-20FF   R/W   xxxxxxxx    Palette RAM
	                  xxx----        (red component)
	                  ---xxx--       (green component)
	                  ------xx       (blue component)
	2400-25FF   R/W   xxxxxxxx    EEPROM
	2800-280F   R/W   xxxxxxxx    POKEY #1
	2810-281F   R/W   xxxxxxxx    POKEY #2
	3000          W   --------    Watchdog
	3400          W   --------    EEPROM write enable
	3800          W   --------    IRQ acknowledge
	3C00          W   --xx----    Coin counters
	              W   --x-----       (right coin counter)
	              W   ---x----       (left coin counter)
	4000-7FFF   R     xxxxxxxx    Banked program ROM
	8000-FFFF   R     xxxxxxxx    Program ROM
	========================================================================
	Interrupts:
		IRQ generated by 32V
	========================================================================

***************************************************************************/


#include "driver.h"
#include "cpu/m6502/m6502.h"
#include "vidhrdw/generic.h"
#include "slapstic.h"
#include "atetris.h"


#define ATARI_CLOCK_14MHz	14318180


/* Local variables */
static UINT8 *slapstic_source;
static UINT8 *slapstic_base;
static UINT8 current_bank;

static UINT8 nvram_write_enable;



/*************************************
 *
 *	Interrupt generation
 *
 *************************************/

static void interrupt_gen(int scanline)
{
	/* assert/deassert the interrupt */
	cpu_set_irq_line(0, 0, (scanline & 32) ? ASSERT_LINE : CLEAR_LINE);

	/* set the next timer */
	scanline += 32;
	if (scanline >= 256)
		scanline -= 256;
	timer_set(cpu_getscanlinetime(scanline), scanline, interrupt_gen);
}


static WRITE_HANDLER( irq_ack_w )
{
	cpu_set_irq_line(0, 0, CLEAR_LINE);
}



/*************************************
 *
 *	Machine init
 *
 *************************************/

static MACHINE_INIT( atetris )
{
	/* reset the slapstic */
	slapstic_reset();
	current_bank = slapstic_bank() & 1;
	memcpy(slapstic_base, &slapstic_source[current_bank * 0x4000], 0x4000);

	/* start interrupts going (32V clocked by 16V) */
	timer_set(cpu_getscanlinetime(48), 48, interrupt_gen);
}



/*************************************
 *
 *	Slapstic handler
 *
 *************************************/

static READ_HANDLER( atetris_slapstic_r )
{
	int result = slapstic_base[0x2000 + offset];
	int new_bank = slapstic_tweak(offset) & 1;

	/* update for the new bank */
	if (new_bank != current_bank)
	{
		current_bank = new_bank;
		memcpy(slapstic_base, &slapstic_source[current_bank * 0x4000], 0x4000);
	}
	return result;
}



/*************************************
 *
 *	Coin counters
 *
 *************************************/

static WRITE_HANDLER( coincount_w )
{
	coin_counter_w(0, (data >> 5) & 1);
	coin_counter_w(1, (data >> 4) & 1);
}



/*************************************
 *
 *	NVRAM handlers
 *
 *************************************/

static WRITE_HANDLER( nvram_w )
{
	if (nvram_write_enable)
		generic_nvram[offset] = data;
	nvram_write_enable = 0;
}


static WRITE_HANDLER( nvram_enable_w )
{
	nvram_write_enable = 1;
}



/*************************************
 *
 *	Main CPU memory handlers
 *
 *************************************/

static MEMORY_READ_START( readmem )
	{ 0x0000, 0x20ff, MRA_RAM },
	{ 0x2400, 0x25ff, MRA_RAM },
	{ 0x2800, 0x280f, pokey1_r },
	{ 0x2810, 0x281f, pokey2_r },
	{ 0x4000, 0x5fff, MRA_ROM },
	{ 0x6000, 0x7fff, atetris_slapstic_r },
	{ 0x8000, 0xffff, MRA_ROM },
MEMORY_END


static MEMORY_WRITE_START( writemem )
	{ 0x0000, 0x0fff, MWA_RAM },
	{ 0x1000, 0x1fff, atetris_videoram_w, &videoram, &videoram_size },
	{ 0x2000, 0x20ff, paletteram_RRRGGGBB_w, &paletteram },
	{ 0x2400, 0x25ff, nvram_w, &generic_nvram, &generic_nvram_size },
	{ 0x2800, 0x280f, pokey1_w },
	{ 0x2810, 0x281f, pokey2_w },
	{ 0x3000, 0x3000, watchdog_reset_w },
	{ 0x3400, 0x3400, nvram_enable_w },
	{ 0x3800, 0x3800, irq_ack_w },
	{ 0x3c00, 0x3c00, coincount_w },
	{ 0x4000, 0xffff, MWA_ROM },
MEMORY_END



/*************************************
 *
 *	Port definitions
 *
 *************************************/

INPUT_PORTS_START( atetris )
	// These ports are read via the Pokeys
	PORT_START      /* IN0 */
	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_COIN2 )
	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_COIN1 )
	PORT_DIPNAME( 0x04, 0x00, "Freeze" )
	PORT_DIPSETTING(    0x00, DEF_STR( Off ) )
	PORT_DIPSETTING(    0x04, DEF_STR( On ) )
	PORT_BITX(0x08, IP_ACTIVE_HIGH, IPT_SERVICE, "Freeze Step", KEYCODE_F1, IP_JOY_NONE )
	PORT_BIT( 0x30, IP_ACTIVE_HIGH, IPT_UNUSED )
	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_VBLANK )
	PORT_SERVICE( 0x80, IP_ACTIVE_HIGH )

	PORT_START      /* IN1 */
	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_BUTTON1 | IPF_PLAYER1)
	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN  | IPF_PLAYER1 | IPF_4WAY )
	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT | IPF_PLAYER1 | IPF_4WAY )
	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT  | IPF_PLAYER1 | IPF_4WAY )
	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON1 | IPF_PLAYER2)
	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN  | IPF_PLAYER2 | IPF_4WAY )
	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT | IPF_PLAYER2 | IPF_4WAY )
	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT  | IPF_PLAYER2 | IPF_4WAY )
INPUT_PORTS_END


// Same as the regular one except they added a Flip Controls switch
INPUT_PORTS_START( atetcktl )
	// These ports are read via the Pokeys
	PORT_START      /* IN0 */
	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_COIN2 )
	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_COIN1 )
	PORT_DIPNAME( 0x04, 0x00, "Freeze" )
	PORT_DIPSETTING(    0x00, DEF_STR( Off ) )
	PORT_DIPSETTING(    0x04, DEF_STR( On ) )
	PORT_BITX(0x08, IP_ACTIVE_HIGH, IPT_SERVICE, "Freeze Step", KEYCODE_F1, IP_JOY_NONE )
	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_UNUSED )
	PORT_DIPNAME( 0x20, 0x00, "Flip Controls" )
	PORT_DIPSETTING(    0x00, DEF_STR( Off ) )
	PORT_DIPSETTING(    0x20, DEF_STR( On ) )
	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_VBLANK )
	PORT_SERVICE( 0x80, IP_ACTIVE_HIGH )

	PORT_START      /* IN1 */
	PORT_BIT( 0x01, IP_ACTIVE_HIGH, IPT_BUTTON1 | IPF_PLAYER1)
	PORT_BIT( 0x02, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN  | IPF_PLAYER1 | IPF_8WAY )
	PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT | IPF_PLAYER1 | IPF_8WAY )
	PORT_BIT( 0x08, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT  | IPF_PLAYER1 | IPF_8WAY )
	PORT_BIT( 0x10, IP_ACTIVE_HIGH, IPT_BUTTON1 | IPF_PLAYER2)
	PORT_BIT( 0x20, IP_ACTIVE_HIGH, IPT_JOYSTICK_DOWN  | IPF_PLAYER2 | IPF_8WAY )
	PORT_BIT( 0x40, IP_ACTIVE_HIGH, IPT_JOYSTICK_RIGHT | IPF_PLAYER2 | IPF_8WAY )
	PORT_BIT( 0x80, IP_ACTIVE_HIGH, IPT_JOYSTICK_LEFT  | IPF_PLAYER2 | IPF_8WAY )
INPUT_PORTS_END



/*************************************
 *
 *	Graphics layouts
 *
 *************************************/

static struct GfxLayout charlayout =
{
   8,8,
   RGN_FRAC(1,1),
   4,
   { 0,1,2,3 },
   { 0*4, 1*4, 2*4, 3*4, 4*4, 5*4, 6*4, 7*4},
   { 0*4*8, 1*4*8, 2*4*8, 3*4*8, 4*4*8, 5*4*8, 6*4*8, 7*4*8},
   8*8*4
};


static struct GfxDecodeInfo gfxdecodeinfo[] =
{
	{ REGION_GFX1, 0, &charlayout, 0, 16 },
	{ -1 }
};



/*************************************
 *
 *	Sound definitions
 *
 *************************************/

static struct POKEYinterface pokey_interface =
{
	2,
	ATARI_CLOCK_14MHz/8,
	{ 50, 50 },
	/* The 8 pot handlers */
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	{ 0, 0 },
	/* The allpot handler */
	{ input_port_0_r, input_port_1_r }
};



/*************************************
 *
 *	Machine driver
 *
 *************************************/

static MACHINE_DRIVER_START( atetris )

	/* basic machine hardware */
	MDRV_CPU_ADD(M6502,ATARI_CLOCK_14MHz/8)
	MDRV_CPU_MEMORY(readmem,writemem)

	MDRV_FRAMES_PER_SECOND(60)
	MDRV_VBLANK_DURATION(DEFAULT_REAL_60HZ_VBLANK_DURATION)

	MDRV_MACHINE_INIT(atetris)
	MDRV_NVRAM_HANDLER(generic_1fill)

	/* video hardware */
	MDRV_VIDEO_ATTRIBUTES(VIDEO_TYPE_RASTER)
	MDRV_SCREEN_SIZE(42*8, 30*8)
	MDRV_VISIBLE_AREA(0*8, 42*8-1, 0*8, 30*8-1)
	MDRV_GFXDECODE(gfxdecodeinfo)
	MDRV_PALETTE_LENGTH(256)

	MDRV_VIDEO_START(atetris)
	MDRV_VIDEO_UPDATE(atetris)

	/* sound hardware */
	MDRV_SOUND_ADD(POKEY, pokey_interface)
MACHINE_DRIVER_END



/*************************************
 *
 *	ROM definitions
 *
 *************************************/

ROM_START( atetris )
	ROM_REGION( 0x18000, REGION_CPU1, 0 )
	ROM_LOAD( "1100.45f",     0x10000, 0x8000, CRC(2acbdb09) SHA1(5e1189227f26563fd3e5372121ea5c915620f892) )
	ROM_CONTINUE(             0x08000, 0x8000 )

	ROM_REGION( 0x10000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "1101.35a",     0x0000, 0x10000, CRC(84a1939f) SHA1(d8577985fc8ed4e74f74c68b7c00c4855b7c3270) )
ROM_END


ROM_START( atetrisa )
	ROM_REGION( 0x18000, REGION_CPU1, 0 )
	ROM_LOAD( "d1",           0x10000, 0x8000, CRC(2bcab107) SHA1(3cfb8df8cd3782f3ff7f6b32ff15c461352061ee) )
	ROM_CONTINUE(             0x08000, 0x8000 )

	ROM_REGION( 0x10000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "1101.35a",     0x0000, 0x10000, CRC(84a1939f) SHA1(d8577985fc8ed4e74f74c68b7c00c4855b7c3270) )
ROM_END


ROM_START( atetrisb )
	ROM_REGION( 0x18000, REGION_CPU1, 0 )
	ROM_LOAD( "tetris.01",    0x10000, 0x8000, CRC(944d15f6) SHA1(926fa5cb26b6e6a50bea455eec1f6d3fb92aa95c) )
	ROM_CONTINUE(             0x08000, 0x8000 )

	ROM_REGION( 0x10000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "tetris.02",    0x0000, 0x10000, CRC(5c4e7258) SHA1(58060681a728e74d69b2b6f5d02faa597ca6c226) )

	/* there's an extra EEPROM, maybe used for protection crack, which */
	/* however doesn't seem to be required to run the game in this driver. */
	ROM_REGION( 0x0800, REGION_USER1, 0 )
	ROM_LOAD( "tetris.03",    0x0000, 0x0800, CRC(26618c0b) SHA1(4d6470bf3a79be3b0766e246abe00582d4c85a97) )
ROM_END


ROM_START( atetcktl )
	ROM_REGION( 0x18000, REGION_CPU1, 0 )
	ROM_LOAD( "tetcktl1.rom", 0x10000, 0x8000, CRC(9afd1f4a) SHA1(323d1576d92c905e8e95108b39cabf6fa0c10db6) )
	ROM_CONTINUE(             0x08000, 0x8000 )

	ROM_REGION( 0x10000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "1103.35a",     0x0000, 0x10000, CRC(ec2a7f93) SHA1(cb850141ffd1504f940fa156a39e71a4146d7fea) )
ROM_END


ROM_START( atetckt2 )
	ROM_REGION( 0x18000, REGION_CPU1, 0 )
	ROM_LOAD( "1102.45f",     0x10000, 0x8000, CRC(1bd28902) SHA1(ae8c34f082bce1f827bf60830f207c46cb282421) )
	ROM_CONTINUE(             0x08000, 0x8000 )

	ROM_REGION( 0x10000, REGION_GFX1, ROMREGION_DISPOSE )
	ROM_LOAD( "1103.35a",     0x0000, 0x10000, CRC(ec2a7f93) SHA1(cb850141ffd1504f940fa156a39e71a4146d7fea) )
ROM_END



/*************************************
 *
 *	Driver init
 *
 *************************************/

static DRIVER_INIT( atetris )
{
	slapstic_init(101);
	slapstic_source = &memory_region(REGION_CPU1)[0x10000];
	slapstic_base = &memory_region(REGION_CPU1)[0x04000];
}



/*************************************
 *
 *	Game drivers
 *
 *************************************/

GAME( 1988, atetris,  0,       atetris, atetris,  atetris, ROT0,   "Atari Games", "Tetris (set 1)" )
GAME( 1988, atetrisa, atetris, atetris, atetris,  atetris, ROT0,   "Atari Games", "Tetris (set 2)" )
GAME( 1988, atetrisb, atetris, atetris, atetris,  atetris, ROT0,   "bootleg",     "Tetris (bootleg)" )
GAME( 1989, atetcktl, atetris, atetris, atetcktl, atetris, ROT270, "Atari Games", "Tetris (Cocktail set 1)" )
GAME( 1989, atetckt2, atetris, atetris, atetcktl, atetris, ROT270, "Atari Games", "Tetris (Cocktail set 2)" )
